/Engine/Source/Runtime/GameplayTags/Classes/GameplayTagsManager.h
Returns the number of parents a particular gameplay tag has. Useful as a quick way to determine which tags may be more "specific" than other tags without comparing whether they are in the same hierarchy or anything else. Example: "TagA.SubTagA" has 2 Tag Nodes. "TagA.SubTagA.LeafTagA" has 3 Tag Nodes.
int32 GetNumberOfTagNodes ( const [FGameplayTag](API\Runtime\GameplayTags\FGameplayTag) & GameplayTag ) const